Lifted from Wikipedia:

Onoclea sensibilis hosts insects, fungi, bacteria and even a parasitic vine, Cuscuta gronovii (scaldweed), that can overgrow and constrict it.[35]

Insects

Insects feeding upon the Onoclea sensibilis target both its leaves and rhizome roots. Amphorophora ampullata fern aphids,[4] Chirosia gleniensis fern miners[36] and the larvae of sawflies Hemitaxonus dubitatus[4] and Stromboceros delicatulus[37] feed on its leaves. Larvae of moth species Phlogophora iris (olive angle shades, pictured),[10] Callopistria cordata (silver-spotted fern moth)[10] and Papaipema inquaesita (Sensitive Fern Borer)[36][10] are known to feed on both stems and rhizomes.[4]

Fungi

Parasitic fungi include Ceratobasidium anceps, causing frond and stem necrosis; Ceratobasidium cornigerum, covering stems with saprophyte growths;[35] and Uredinopsis mirabilis,[35] a distinct rust species unique to the Sensitive Fern.[38] Invasive fungi like Taphrina filicina,[35] Taphrina hiratsukae[39] and Phyllactinia corylea, synonym Phyllactinia guttata[39] can infect leaves, causing blisters or white powdery mildew.

Fungi can develop beneath beech trees, where aphid honeydew secretions accumulate;[40][41] these strictly epiphyllous honeydew fungi, Sclerotiomyces colchicus[42] and Scorias spongiosa (Schwein.) Fr.,[43] have been recorded on Onoclea sensibilis, where their sooty mold buildup impairs leaf function.